杭州一品楼

Carbon nanotubes may be the key to shrinking down transistors and squeezing more computer power into less space.

Historically, the number of transistors that can be crammed onto a computer chip has doubled every two years or so, a trend known as Moore’s law. But that rule seems to be nearing its limit: Today’s silicon transistors can’t get much smaller than they already are.

Carbon nanotubes may offer a sizable solution. In the June 30 Science, IBM researchers report a carbon-nanotube transistor with an overall width of 40 nanometers — the smallest ever. It’s about half the size of typical silicon transistors.

Researchers have created carbon-nanotube transistors with certain supersmall components before, but the whole package was still bulky, says study coauthor Qing Cao of IBM’s Thomas J. Watson Research Center in Yorktown Heights, N.Y. The new study confirms that, in terms of size, carbon-nanotube transistors can beat out silicon — and that’s no small feat.

A new insect-inspired tiny robot that can move between air and water is a lightweight.

Weighing the same as about six grains of rice, it is the lightest robot that can fly, swim and launch itself from water, an international team of researchers reports October 25 in Science Robotics. The bot is about 1,000 times lighter than other previously developed aerial-aquatic robots. In the future, this kind of aquatic flier could be used to perform search-and-rescue operations, sample water quality or simply explore by air or sea.
To hover, the bot flaps its translucent wings 220 to 300 times per second, somewhat faster than a housefly. Once submerged, the tiny robot surfaces by slowly flapping its wings at about nine beats per second to maintain stability underwater.

For the tricky water-to-air transition, the bot does some chemistry. After water has collected inside the machine’s central container, the bot uses a device to split water into hydrogen and oxygen gas. As the chamber fills with gas, the buoyancy lifts the vehicle high enough to hoist the wings out of the water. An onboard “sparker” then creates a miniature explosion that sends the bot rocketing about 37 centimeters — roughly the average length of a men’s shoe box — into the air. Microscopic holes at the top of the chamber release excess pressure, preventing a loss of robot limbs.
Still, the design needs work: The machine doesn’t land well, and it can only pierce the water’s surface with the help of soap, which lowers the surface tension. More importantly, the experiment points to the possibilities of incorporating different forms of locomotion into a single robot, says study coauthor Robert Wood, a bioengineer at Harvard University.

Overtime is going to look a little bit different in college football games during the 2021 season. The NCAA has once again made some minor tweaks to its overtime rules.

Why? It's all in the name of bringing the game to a quicker conclusion.
The NCAA has made shortening overtime its mission since Texas A&M beat LSU 74-72 in a seven overtime game during the 2018 season. As exciting as that game was, it was long. More than 200 snaps were played, which is certainly not ideal for the players on the field.

So, how is the NCAA changing its overtime rules for 2021? Here's everything you need to know about the differences in overtime this season and how it compares to previous seasons.
College football overtime rules 2021
The NCAA amended its overtime rules in 2021 in an attempt to lessen the number of plays run in an overtime period. Teams are now required to run a two-point conversion after a touchdown beginning in the second overtime period. Previously, that began in the third overtime period.

Additionally, teams will begin running alternating two-point conversion attempts if the game reaches a third overtime. So, it's essentially a one-play drive. The goal of this is to limit the number of plays run from scrimmage by each team.

Here are the rest of the college football overtime rules for the 2021 season.

At the end of regulation, the referee will toss a coin to determine which team will possess the ball first in overtime. The visiting team captain will call the toss. The winner gets to choose to either play offense or defense first or chooses which side of the field to play on. The decision cannot be deferred.
The teams that loses the coin toss must exercise the remaining option. They will then have the chance to choose first from the four categories in the second overtime and subsequent even-numbered OT periods. The team that wins the toss will have the same options in odd-numbered OT periods.
In each of the first two overtime periods, teams are granted one possession beginning at the opponent's 25-yard line, unless a penalty occurs to move them back. The offense can place the ball anywhere on or between the hash marks.
Each team is granted one timeout per overtime period. Timeouts do not carry over from regulation nor do they carry over between overtime periods.
Each team retains the ball until it fails to score, fails to make a first down or turns the ball over.
Beginning with the second overtime period, teams must attempt a two-point conversion after scoring a touchdown.
Beginning with the third overtime period, teams will begin to run alternating two-point conversion plays instead of offensive possessions.
The college football overtime rules are the same in both the regular and postseason.
College football overtime rule change proposals
The most recent overtime rule change proposal was passed by the NCAA in 2021. It was made in the name of shortening games and limiting offensive reps, as previously stated.

Below are the rule changes that were ratified for 2021:

Beginning with the second overtime period, teams must attempt a two-point conversion after scoring a touchdown.
Beginning with the third overtime period, teams will begin to run alternating two-point conversion plays instead of offensive possessions.
History of college football overtime rules
Up until 1996, most NCAA games did not go to overtime. They simply ended in a tie. However, the governing body adopted overtime rules after pushback on some important matchups ending all square.

The initial overtime rules were in place for quite a while. Each team got the ball at the opponent's 25-yard line and retained the ball until it failed to score, failed to make a first down or turned the ball over. Teams alternated possessions until a team emerged as a victor.

Then, in 2019, the NCAA made a couple of changes in the name of shortening the game. That's when they added the two-point conversion rule, so teams had to start attempting a two-point conversion starting in the third overtime. Then, after five overtimes, teams would start running alternating two-point conversion plays. These changes were, basically, a direct response to the Texas A&M vs. LSU game.

In 2021, the rules were tweaked again, as teams must run two-point conversions in the second overtime period and will begin alternating two-point plays when the third overtime begins.

Prior to the 2021-22 season, the NBA's historic 75th season, Stephen Curry was hot on the heels of Hall of Famer Ray Allen to become the all-time leader for most 3-pointers made.

Entering the season, Curry needed 142 3-pointers needed to surpass Allen, and 12 games into the season, he's knocked off 76 of the latter's lead.
It's still early but Curry is averaging a career-high 5.4 makes per game, a shade above his previous career-high of 5.3 which he set last year in 63 games. During the 2015-16 season in which he set the all-time single-season record with 402 en route to winning his second straight MVP award, Curry averaged 5.1 makes in 79 games.
Top 10 players on the all-time leader for most made 3-pointers
Curry is one of three active players in the Top 10 with James Harden and Damian Lillard being the other two players.

 Player  3-pointers

1. Ray Allen 2,973
2. Stephen Curry 2,908
3. Reggie Miller 2,560
4. James Harden 2,489
5. Kyle Korver 2,450
6. Vince Carter 2,290
7. Jason Terry 2,282
8. Jamal Crawford 2,221
9. Paul Pierce 2,143
10. Damian Lillard 2,087
    LeBron James, who ranks 11th, could break into the Top 10 and increase the list to four active players later this season.

When will Stephen Curry surpass Ray Allen?
Curry has hit 42 of the 76 3-pointers in just five games including a red-hot shooting game against the LA Clippers, where he erupted for 45 points that started with a perfect 25-point first quarter and an overall 8-of-13 efficiency from beyond the arc and a 50-piece against the Atlanta Hawks.

As of Nov. 16, the baby-faced assassin, who is considered to be the greatest 3-pointer shooter in NBA history, needs 76 more 3-pointers to overtake Allen.
Going by his season average of 5.4 3-pointers per game, Curry would take anywhere around 14 games to jump to the No. 1 spot on the all-time charts.

That many games mean Curry could make NBA history in mid-December, provided of course that he misses no games moving forward.

Warriors upcoming 2021-22 schedule
With that projection, Curry would likely make NBA history on the road as Golden State would be on a five-game Eastern Conference road trip in mid-December.

14 games ahead on the Warriors schedule will see the team in Indiana, the birthplace of basketball. 15 games ahead will see the Warriors at the iconic Madison Square Garden playing the Knicks.

In case Curry takes a couple more games to surpass Allen, he has a couple of more iconic locations awaiting him in Boston - home of one of the oldest franchises which is tied for the most champions in NBA history - and Toronto - the capital of the birth country of James Naismith, the sport's inventor.

Warriors upcoming schedule
Date Opponent Time (ET)
Nov. 10 vs. Timberwolves 10:00 pm
Nov. 12 vs. Bulls 10:00 pm
Nov. 14 at Hornets 7:00 pm
Nov. 16 at Nets 7:30 pm
Nov. 18 at Cavaliers 7:30 pm
Nov. 19 at Pistons 7:00 pm
Nov. 21 vs. Raptors 8:30 pm
Nov. 24 vs. 76ers 10:00 pm
Nov. 26 vs. Trail Blazers 10:00 pm
Nov. 28 at LA Clippers 3:30 pm
Nov. 30 at Suns 10:00 pm
Dec. 3 vs. Suns 10:00 pm
Dec. 4 vs. Spurs 8:30 pm
Dec. 6 vs. Magic 10:00 pm
Dec. 8 vs. Trail Blazers 10:00 pm
Dec. 11 at 76ers 8:30 pm
Dec. 13 at Pacers 7:00 pm
Dec. 14 at Knicks 7:30 pm
Dec. 17 at Celtics 7:30 pm